Chemical structure of a new family of bile pigments from human urine.

Seven bilirubin metabolites negative to the diazo reaction were identified in the urine of healthy persons by enzyme-linked immunosorbent assay (ELISA) using the anti-bilirubin monoclonal antibody 24G7. Two of the seven metabolites were isolated and their chemical structures were determined using fast-atom bombardment-mass spectroscopy (FAB-MS) and 1H-NMR. The two metabolites are 1,14,15,17-tetrahydro-2,7,13-trimethyl-1,14- dioxo-3-vinyl-16H-tripyrrin-8,12-dipropionic acid and 1,14,15,17-tetrahydro-3,7,13-trimethyl-1,14-dioxo-2-vinyl-16H- tripyrrin-8,12-dipropionic acid. They are regioisomers of each other. The two bilirubin metabolites are novel tripyrrole biocompounds and belong to a third group of bile pigments following biliverdin and bilirubin. We gave these compounds the generic names biotripyrrin-a and biotripyrrin-b, respectively.

Laboratory evaluation of liver disease.

With respect to liver disease, the primary function of the laboratory is to identify its presence. Tests are not available that permit a specific diagnosis and an accurate prognosis. Several tests should be present in a minimum data base that can help identify hepatobiliary disease. They are ALT, SAP, total serum bilirubin, urine bilirubin, cholesterol, albumin, BUN, glucose, red cell morphology, and urine sediment. It is sometimes possible to tentatively identify whether a disease is primarily hepatocellular or biliary from the pattern of changes that occur in these tests. In addition, an estimate of the severity is sometimes possible when abnormal values are extreme. The keys are to avoid overinterpretation, use serial evaluations, and rely on a liver biopsy when definitive answers are needed. If liver disease is suspected but there are only marginal changes in the routine tests, the more sensitive tests of function, BSP retention and ammonia tolerance, are warranted. In the future, as more knowledge is gained about the responses of ARG, GGT, and ICG retention to naturally occurring diseases, these tests may join or replace some of those currently used. Also, as the ability to accurately and economically measure the various bile acids improves, a sensitive, yet noninvasive, method to detect and define modest changes in hepatobiliary function may result.

Cholelithiasis--areview of 130 cases.

One hundred and thirty cases of cholelithiasis were studied in the surgical wards of the Institute of Postgraduate Medicine and Research, Dacca. Geographical distribution, pattern of clinical features, results of biochemical, microbiolgical, histopathological and other investigations have been recorded.

Heterogeneity of bile pigments formed by the breakdown of haemoglobin in the isolated male-dog kidney.

Normothermic perfused isolated male-dog kidneys formed radioactive bile pigments by the breakdown of radioactive haemoglobin prepared from [2-14C]glycin. After column chromatographic separation and preparation of dipyrrolic azopigments, 86.3 +/- 2.2% of the bile pigments seemed to be conjugated bilirubin. Thin-layer chromatographic separation of the azopigments of ethyl anthranilate revealed a good correlation between photometric scanning, radiochromatographic scanning and the radioactivity of the azopigments scraped off the thin-layer glass plates and counted in a liquid scintillation counter. Although the same heterogenity of the azopigments was observed as in dog bile, the isolated male-dog kidney formed significantly less alpha2- and significantly more gamma-fractions.

Heterogeneity of bile pigment conjugates as revealed by chromatography of their ethyl anthranilate azopigments.

1. Azopigments derived from conjugated bile pigments by coupling with the diazonium salt of ethyl anthranilate are analysed conveniently by quantitative t.l.c. or by column chromatography on CM-cellulose. 2. By chromatographic studies combined with a series of chemical tests six groups of azopigments were demonstrable in preparations from bile and from icteric urine of man. Azobilirubin and its beta-d-monoglucuronide have hitherto been considered to be the only major derivatives that can be obtained from human bile pigments. In the present work, other azopigments accounted for 30-40% of the total azopigment material, and the amounts of these showed considerable variation among biological fluids. 3. The divergence of the present results from earlier work is probably related to the use of milder diazotization conditions and of chromatographic techniques with a high resolving power. 4. The thin-layer chromatographic systems developed allow rapid and quantitative analysis of azopigments derived from bile pigments.